1. Field
Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to transitioning of mobile devices within a wireless communication network between multiple radio access technologies (RATs).
2. Background
Wireless communication networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, and the like. These wireless networks may be multiple-access networks capable of supporting multiple users by sharing the available network resources. Such networks, which are usually multiple access networks, support communications for multiple users by sharing the available network resources.
One example of such a network is the Universal Terrestrial Radio Access Network (UTRAN). The UTRAN is the radio access network (RAN) defined as a part of the Universal Mobile Telecommunications System (UMTS), a third generation (3G) mobile phone technology supported by the 3rd Generation Partnership Project (3GPP). Examples of multiple-access network formats include Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks, and Single-Carrier FDMA (SC-FDMA) networks.
A wireless communication network may include a number of base stations or node Bs that can support communication for a number of user equipments (UEs). A UE may communicate with a base station via downlink and uplink. The downlink (or forward link) refers to the communication link from the base station to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the base station. UEs may travel within the wireless communication network and may change the base stations with which they communicate. Such changes may occur while the UE is in idle mode operation or active mode operation and may involve utilizing different radio access technologies (RATs) which have correspondingly different features. As the demand for mobile broadband access continues to increase, the possibility that a mobile device will encounter different RATs increases. Thus, research and development continue to advance, not only to meet the growing demand for mobile broadband access, but to advance and enhance the user experience with mobile communications.